Allow branch.*.merge to talk about remote tracking branches.

People often get confused if the value of branch.*.merge should
be the remote branch name they are fetching from, or the
tracking branch they locally have.  So this allows either.
Signed-off-by: NJunio C Hamano <junkio@cox.net>

git-parse-remote.sh

@@ -146,8 +146,12 @@ canon_refs_list_for_fetch () {
 		else
 			for merge_branch in $merge_branches
 			do
-			    [ "$remote" = "$merge_branch" ] &&
-			    dot_prefix= && break
+			    if	test "$remote" = "$merge_branch" ||
+				test "$local" = "$merge_branch"
+			    then
+				    dot_prefix=
+				    break
+			    fi
 			done
 		fi
 		case "$remote" in